A coepoeation



No. 750,239. PATENTED JAN. 19, 1904. W. J. BOWEN. ELEGTRICALLY HEATED SOLDERING IRON.

APPLICATION FILED AUG. 17, 1903.

lby www@ Patented January 19, 1904.

UNITED STATES PATENT OEEICE.

WILLIAM J. BOVEN, OF CLEVELAND, OHIO, ASSIGNOR TO THE VILLIAMS- ABBOTT ELECTRIC COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

ELECTRlCALLY-HEATED SOLDERING-IRON.

SPECIFICATION forming part of Letterslatent No. 750,239, dated January 19, 1904.

Application filed August 17, 1903. Serial No. 169,732. (No model.)

To all whom, it may concern,.-

Be it known that I, WILLIAM J. BOWEN, a citizen of the United States of America, and a resident of Cleveland, in the county of Cuyahoga and State of Ohio, have invented certain new and useful Improvements in Electrically- Heated Soldering-Irons, of which the following is a specication.

My invention relates to improvements in electrically-heated soldering-irons, and has for its principal objects the construction of a device wherein the removable soldering-tip and its socket are preserved from deterioration, the operative parts are made readily removable from the handle portion and are respectively insulated and preserved against the effects of heat, and the heating-conductor is securely insulated against making electrical contact with its metallic core or mounting. It has been found in practice that while readily removable and replaceable soldering-tips are a practical necessity in this class of apparatus, the sockets therefor and the tip-fastenings are usually liable to oxidation and deterioration from the effects of the acid or heat. Not infrequently a tip will be found practically united or fused to its socket under the combined effects of these two forces and is removed therefrom only by breaking said socket or receptacle or the engaging parts of the tip. The intense heat of the coil is communicated through the stem or shank to the handle, usually of wood, which chars out or shrinks away from the stem and requires replacement unless the shank be made of unusual length. Metallic cores or spools, which most readily conduct the heat of the coil, not infrequently ground or short-circuit the heating-conductor, and this difficulty is commonly located 40 in the rear spool-head, where the conductor passes out to the handle portion and energizing-circuit. When a coil has short-circuited, is broken, or requires rewinding or other attention or repair, it becomes necessary completely to dismantle soldering-irons not made readily separable in accordance with my improvements.

Having in mind these undesirable features of devices in general use, it has been my purpose to provide a structure obviating the same, which I have attained in the solderingiron of my invention herein set forth. This I may describe in a preliminary way as consisting of the usual heating-coil wound upon a suitable metallic core suitably tapped out to receive a threaded exterior soldering-tip. Between the mounting portions of the tip is interposed a stratum of inert material adapted to protect them, such as graphite. A lava washer of peculiar form disposed at the rear spool-head accommodates and insulates the extremities of the heating-cond uctor. The shank uniting the heater and handle is of conveniently short length, being provided with mica or similar insulation against the passage of heat, while the handle preferably is hollow and has inner binding-posts, with which are connected the heater-wires and the conductors of the external circuit. By withdrawing, preferably, a single accessible screw in the casing the heater is at once separable from the handle portion.

Further details and advantageswill appear upon making reference to the accompanying drawings, wherein- Figure I is a longitudinal section of the entire device, showing my improvements in enlarged detail; Fig. II, an end view of the spool or core, partly broken away; Fig. III, a crosssectional view through the handle indicated on line III III, Fig. I; Fig. IV, an enlarged view showing the removable soldering-tip and its manner of attachment, and Fig. V a small side elevation illustrating the entire device fully assembled and equipped.

The same character of reference is employed throughout the several figures to indicate similar parts. y

Three principal separable parts are comprised in my improved soldering-iron, which are the handle portion, mounting the heating apparatus, and the removable soldering-tip.

The handle proper is hollow and comprises two telescoping sections /t h2. On the end of the former are provided the two-way interior binding-posts p pz, connecting with the wires y w of the external circuit and the doubled or looped extremities c2 of the heating-conductor c'. Said extremities are inelosed in asbestos sleeves and are carried within the hollow handle portion to the rear of the spoolhead, whence they pass through nipples Z2 in the lava washer Z to the body of the heatingcoil c. The washer and its integral nipples are so formed or molded as to safely carry the conducting-wires in position to prevent short-circuiting by any metallic part of the deviceesueh as the core, the rear supporting' metallic head thereof, through which these nipples extend, or the casing-it being obvious that the wires when stayed by the elong'ated nipples must remain in proper relation to the other parts of the appliance. Heatingconductor or resistance-wire c is wound between layers of mica in the usual manner upon a copper or metallic core or spool s, the rear head of said spool being bored to accommodate the projecting nipples Z2 of the lava washer Z, which effectively insulate the heating-conductor at this vulnerable point.

A tubular stem or shank has a iianged head /L'L at one end, and the other end is inserted in the bored section /Z of the wooden handle, where it is secured by means of ang'ularly-disposed screws f2, passing through the heavy ferrule f, the sleeve of the handle, and entering tapped holes in the shank, thus clamping' said shank firmly within the ferrule and inclosing handle. Screwf13 independently secures the ferrule and handle. Accordingly it is seen that the stem or shank is held firmly in the handle, even though the wood sln'ink or char away from the lower end of said shank in a manner ordinarily causing it to loosen.

rlhe end section 7a2 of the handle is in the form of a cap held in place by long screws engaging' section ZL', from which it may readily be removed, thus fully exposing and making' perfectly accessible for any desired purpose the two-way binding posts or terminals carried on the end of section h. A close coil m', of stiff spring-wire, prevents the binding' or breakage of the inelosed entering wires w.

A thick section fm, of superposed disks of mica or other suitable heat-insulator, is interposed between the flanged head and the inturned lower end of the inclosing' shell or casing' (Z, which, in connection with the interiorly-disposed disk (Z2, preferably of metal and seated upon mica, securely and rigidly mount these parts in a unitary structure. The casing and its contained heating-coil are thus very effectively mounted upon the handle in a manner precluding the passage by conduction of undue heat to said handle and without the necessity of lengthening' the shank to the extent of making the soldering-iron unwieldy or inconvenient to use.

The heating' apparatus is secured in the casing by means, preferably, of a single screw s2, the forward or outer head of the spool s being ianged or shouldered to lit snugly within the casing', seat the screw, and a'll'ord a rigid mounting' for the connected parts. Upon removing' the said screw .s2 and detaching the heating-conductor from the binding-posts p p2 it is evident that the heating apparatus may be withdrawn from the handle portion with ease for any purpose desired. ',lhus the external conductors need not be disconnected no1' are they brought into contact with the heated parts of the soldering-iron or the core. These conductors are of copper, and it is much better in practice to double the extremities of the resistance-wire to increase their conductivity and bring them down to binding-posts common to the external conductors of the energizing-circuit, as described, than to make direct connection.

rlhe outer end of the spool s is suitably tapped to receive the corresponding'ly-tappcd end of the removable and replaceable copper soldering-tip fr. This, as seen, is provided with a relatively wide shou ld er 1', closely engaging thel exterior of the socket or receptacle and the end of said spool and when firmly seated or screwed into place prevents the access of acid to or the oxidation or fusion of the mounting' parts. Preferably these engaging parts are also coated with a thin layer or covering' of graphite g, which is of material assistance in preventing deterioration of the socket and inserted tip. l ere the removable tip and its socket not screw-threaded and. no provision made for the exclusion of ai r and acid or its fumes the mounting' parts would become damaged under the effects of heat quite rapidly indeed, and the replacement of the core or entire heating-coil would be required much sooner than when my improved eonstruction is employed. Accordingly a screw-joint for uniting' these parts is much to be preferred to other forms of mounting, permitting' the access of acid and air to the engaging parts even in restricted volumes or quantities. lhe efliciency of the screwjoint, moreover, is materially increased by the interposed stratum of graphite in this particular, not only in permitting a closer joint to be formed between the parts, but also because of the fact that this covering very eifecti vely prevents oxidation and the action of acids upon the metal parts.

Having' now described and shown a soldering-iron embodying my improvements, l claim as new, and desire to secure by Letters Patent, the following:

4l. In an electrically-heated soldering-iron, the combination with the heating-coil, of the metallic core or spool whereon it is mounted, the same being provided with a tapped receptacle or socket at its forward end, a removable soldering-tip similarly tapped and adapted to screw into the socket, and a covering of graphite or similar substance, adapted to aslOO sist in protecting the engaging parts of the screw-joint, substantially as set forth.

2. In a device of the class described, the combination with the heating-coil, of its metallic spool or core carrying the same, said core being provided with a suitable receptacle or socket, a removable tip portion adapted to be mounted in said receptacle, and an interposed layer of inert material such as described, adapted to protect the mounting portions of said tip and its receptacle or holder, substantially as set forth.

3. In an electrically-heated soldering-iron, the combination with the heating-coil, of the spool whereon it is mounted, the same being provided with a receptacle at its forward end, a removable soldering-tip mounted therein, and a stratum or covering of inert material such as described, assisting in protecting the mounting parts of the tip, substantially as set forth.

4. In an electrically-heated soldering-iron, the combination with the heating-coil, of a rimmed, tubular casing containing the same, a flanged shank or stem carried by the handle, and a section of heat-insulating material closing the rimmed end of the casing and mounted therein, the same being interposed directly between the lianged portion of the shank and the casing to form an auxiliary mounting' and prevent the access of heat to the handle, substantially as set forth.

5. In an electrically-heated appliance of the class described, the combination with a spool or core, of the heating-conductor wound thereon between insulating-wrappings, and a heatresisting washer having bored projecting' nipples, mounted in the head of the spool, through which nipples the extremities of the heatingconductor are brought out and insulated, substantially as set forth.

6. In an electrically-heated appliance of the class described, the combination with amounting spool or core, of the heating-conductor insulated thereon, and a heat-resisting washer such as lava, having elongated, outwardly-extending nipples bored to receive the ends of the heating-conductor and carry them past the surrounding metallic parts, whereby the conductors are insulated and prevented from being broken for a distance beyond the rear of the heating-coil, substantially as set forth.

7. In an electrically-heated appliance of the class described, the combination with the heating apparatus, of the tubular stem or shank carrying the same, the handle mounting' said shank, the heavy ferrule inclosing the telescoping end portions of said parts, a screw uniting thehandle and ferrule, and angularlydisposed screws entering tapped holes in the inserted end of the shank and clamping it within the handle and ferrule, substantially as set forth.

Signed at Cleveland, this 10th day of August, 1903, in the presence of two subscribing witnesses.

VILLIAM J. BOWEN. IIitnesscs:

CHAs. C. CADDEN, ALBERT LYNN LAWRENCE. 

